Polyester latex provides toner with desirable rheologic properties in fusing and low minimum fix temperature. But polyester toner is sensitive to RH. Humidity impacts triboelectric charge of the polyester toner particles, which in turn, impacts xerographic performance and image quality.
Toner charge can be enhanced with external additives. That option, however, has shortcomings. The replenisher of the development system is subject to high forces imparted by, for example, the development auger, which causes impaction of additives into the toner surface. Toner particle residence time in the development system positively correlates with degree of additive impaction. Embedment of the external additive into the surface of the toner particle leads to undesirable toner charging behavior and poor print quality (in particular, areas of low toner coverage).
Accordingly, there remains a need to stabilize charge of toner particles prepared with polyester resins to capitalize on the desirable rheologic properties. That problem was addressed herein by preparing a hybrid toner comprising both polyester resin and styrene/acrylate resin in the core.